Radio tuner with vacuum assist



Aug. 26, 1958 J. H. TEAF RADIO TUNER WITH VACUUM ASSIST Filed Dec. 21, 1955 2 Sheets-Sheet 1 2 INVENTOR.

JOHN H. TEAF BY flunk, i ATTORNEY 6, 1958 J. H. TEAF 2,848,900

RADIO TUNER WITH VACUUM ASSIST Filed Dec. 21, 1953 2 Sheets-Sheet 2 w w m Q m 2 cu co m N) 2 LL N Q LL i v g 2 :2 m

canton-ma INVENTOR. JOHN H. TEAF ATTO R N E YS United rates Patent RADIO TUNER wrrrr VACUUM ASSIST John H. Teaf, Merchantville, N. J., assignor to Radio Condenser Company, Camden, N. 3., a corporation of New Jersey Application December 21, 1953, Serial No. 399,214 9 Claims. (Cl. 74-1033) This invention relates to radio tuners and has particular reference to push button type tuners having vacuum assists for facilitating push button tuning operations. The invention is particularly adapted to automobile radios, the vacuum being derived from the engine intake manifold.

Automobile push button radio tuners involve the necessity for exertion of substantial finger pressure upon push buttons for effecting tuning. Provisions have, in the past, been made for assisting such push button tuning by electromechanical means but these have had various drawbacks. First, at the low voltages available from the automobile electrical system, heavy currents must be drawn to secure any substantial amount of power. In order to avoid undesirable bulk in a tuner, the coils for effecting assist have been so designed that they will tolerate the current for only a very short period without burning out. The result is that maintenance of finger pressure on a push button may lead to destruction of the coil or coils involved. Secondly, the operation of a solenoid is essentially violent and produces undesirable shock and noise.

It is the broad object of the present invention to provide a radio tuner, utilizing for tuning assist purposes the available vacuum existing in the intake manifold of a running engine. Such a vacuum action will produce a shockless and quiet operation. In accordance with the present invention, the vacuum assist arrangement is associated with a conventional type of push button tuner mechanism which may be operated for tuning purposes even when the vacuum is unavailable because of the stopped condition of the engine. In such case, it is only necessary to exert the usual pressure upon a push button.

The foregoing and other objects of the invention, particularly relating to details of construction and operation productive of reliable and proper action, will become apparent from the following description, read in conjunction with the accompanying drawings, in which:

Figure 1 is a diagrammatic plan view, partially in section and with various parts broken away to show a mechanism constituting a preferred embodiment of the invention;

Figure 2 is a section taken on the broken surface, the trace of which is indicated at 22 in Figure l; and

Figure 3 is an elevation of the push button assembly viewed from the side opposite that shown in Figure 2.

The various parts illustrated are carried by a suitable sheet metal frame which is of conventional type of construction and is shown only fragmentarily to avoid unneccessary complexity of the drawings and obscuring of operating parts. There is indicated at 2 a slide gulded in conventional fashion for horizontal movements in the frame, there being secured to this slide by adjustably positioned rods 4 the movable cores of conventional tuning reactances which are not illustrated. As will be evident, the invention is equally applicable to condenser tuning, condensers being connected to controlling devices in conventional fashion. The slide 2 is connected,

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by links 6 to a paddle assembly generally indicated at 8 which comprises a pair of rods 10 and 12 and which is pivoted as indicated at 14 in the frame. At its righthand end, as viewed in Figure 1, this assembly is secured to an anti-backlash gear segment 16 which meshes With a pinion 18 mounted on a shaft 20 to which is secured a clutch member 22 cooperating with a second clutch member 24 which is canied by a hub 26 slidable on the shaft and provided with a groove into which there projects the end 28 of a transverse slide 30 mounted for transverse movements in the frame and normally urged to its right-hand position by a spring 32 reacting between the slide 30 and a fixed anchorage in the frame to produce normal engagement of the clutch elements 22 and 24. The clutch element 24' is formed with teeth to provide a crown gear 24 which meshes with the pinion 36 provided on the end of a shaft 38 which is pivoted in the frame loosely at 4%) and guided for slight horizontal movements by a slot provided in a frame bracket 41. The forward end of the shaft 38 is provided with a flexible disc 42 the periphery of which has pinched frictional engagement between discs 42 carried by a forwardly projecting shaft 44 which carries the conventonal manual tuning knob (not shown).

Push button assemblies, designated generally 46, are provided for push button tuning, and each of these comprises a push button 48 which is secured to a slide member 50 having flanges 52 embracing the outer portion of a second slide member 54 which has a reduced inner projecting extension 56 guided in the frame and surrounded by a compression spring 58 which reacts between the frame and a shoulder 60 (Figure 3) on the last mentioned slide member. Pivoted to each slide member 54 at 62 is a cam 64. A lever 66 is pivotally mounted in a bracket 68 and has its outer end arranged to overlie a projection '70 formed by a portion of the slide member 5t). A leaf spring 72 urges the forward end of lever 66 toward the right, as viewed in Figure l, to release its rear end 74 from its cam 64 when the projection 76 is withdrawn forwardly from beneath the forward end of lever 66 for resetting of the tuner. When the parts are in normal operating position as illustrated in the figures, the projection engages the lever66 which acts as a strong spring and serves to clamp securely the cam 64 in its adjusted position. The inner end of each of the slide extensions 56 is arranged to engage a corresponding cam 75 on the slide 30.

The parts so far described are entirely conventional, the push button assembly, in particular, being of the type illustrated in my patent 2,301,090, dated November 3, 1942. Details of construction and operation of this conventional mechanism form no part of the present invention and, hence, the manual unassisted tuning operations need only be briefly described.

Continuous knob tuning is effected merely by rotation of shaft .4 which through its connections to the paddle assembly, including the clutch 22, 24, serves to actuate the slide 2 to adjust the cores of the conventional reactance tuning elements. When push button tuning is desired, the chosen push button is pushed inwardly against the action of its spring 58. The first operation is that of effecting movement to the left of slide 30 by the action of the extension 56 on the corresponding cam 75 with resultant disengagement of the clutch elements 22 and 24. This serves to relieve the tuning effort of the necessity for driving the manual tuning knob assembly which, in view of the reduction gearing, would ofier substantial frictional resistance to being driven. As the slide moves further inwardly, its locked cam 64 will engage one of the rods 10 or 12, depending upon their previous position, and will effect rocking of the paddle until the cam engages both of the rods. This positions the tuning elements in proper relationship for tuning to the selected frequency. Upon release of the push button, it is moved to its normal outer position by its spring 58 and the clutch is reengaged by spring 32 to be in position for manual tuning. Settings of the earns 64 are effected by pulling the push buttons 48 outwardly to release the cams. When a particular cam has been thus released, the tuning to a desired station may be effected with the manual tuning knob and then the push button is moved inwardly to produce engagement of its'cam 64, which is now in condition to rock freely, with the rods and 12 in the position to which they were set by the manual tuning knob operation. Further movement of the push button then causes the projection 70 to move under the outer end of lever 66 to effect clamping of the cam in the position which it has newly assumed.

The conventional mechanism so far described is modified in accordance with the present invention as follows, the modification involving, primarily, only additions without substantial changes in the conventional parts:

To each of the slide members 54 there is pivoted at 76 a lever 78 provided with a hook 80 arranged to be engageable by the edge 83 of a slide 82 when the corresponding push button is moved inwardly sufficiently to permit the cam edge 84 of the lever to pass the edge of a slot through which the lever 78 projects in a portion 86 of the frame. The cam 84 is so located, as shown in Figure 2, that when the corresponding push button is in its outer position the lever 78 israised clear of the slide 82.

When the push button is moved inwardly, the lever 78,

which is loosely pivoted to its slide member, will drop below the level of the upper surface of slide 82 into position to be engaged by edge 83. The slide 82 is mounted for horizontal sliding movement in the frame, projecting through slots therein which are not illustrated, and is constrained to parallel movement by the provision of racks formed by punched out openings 88 at its ends 7 which engage pinions 90 carried by a shaft 92 mounted in the frame. A spring 93 normally urges the slide 82 to a limited forward position. The slide 82 is provided with an arm 94 which at its rear end 96 is turned upon itself to provide an opening embracing a rod 98 provided with a head 100 between which and theend 96 there is provided a compression spring 102. The rear end of the rod 98 carries a piston 104 which is arranged to slide in a cylinder 106. A close sliding fit is provided which need not involve packing if the tuner is of the freely operating type described, though packing maybe used if desired to augment the assisting action.

The cylinder 106 is provided with a port 108 with which there is aligned the opening 110 of a nipple 112 on which there is located the end of a tube 114 the other end of which may be connected to a fitting on the engine intake manifold. The cylinder and nipple are both mounted on the frame and between them there is arranged to slide a valve 116 which is provided with a port 118 which may be brought into alignment with the-port 108 and opening 110. A spring 120 normally urges the valve 116 to the left-hand position illustrated in Figure 1 in which communication between the port 108 and opening 110 is cut off, and the port 108 is opened to the atmosphere through the slot 121 in the valve. A lever 122 is pivoted to the frame at 124 and is urged against astop pin 128 by a spring 126 anchored to the frame. The end 130 of this lever is arranged to be engageable by a pin 132 carried by the slide 30. The rear end of the lever 122 is provided with an arcuate head 134 which cooperates with a pin 136 horizontally slidable through the valve 116 and urged forwardly by a spring 140, hearing against its disc head 138. An arm 142 is pinned at 143 to the piston rod 98 and is guided in the frame with its head 144 in position to be moved to engage the disc The operation of the described mechanism is as follows:

Assuming the engine running, so that, there exists a vacuum in the tube 114 and opening 110, if the operator presses one of the buttons 48, the initial movement of the corresponding slide assembly causes the cam 84 to clear the frame edge on which it rests so that the lever 78 drops by gravity to present the hook 80 beyond the edge 83 of slide 82. At the same time, the corresponding cam is engaged by the end of the slide member 56 and moves to the left to release the clutch. The pin 132 then engages the forward end of lever 122, causing its rear end' 1 4 to engage pin 136 causing movement of slide 116 to- Ward the right to bring into alignment the port 108 and opening 110. Evacuation of the cylinder then takes place with the result that the piston 104 moves rearwardly, carrying with it the slide 82. Assuming for the present that the pull by the piston is suflicient, the edge 83 of the slide will engage the hook of the lever '78 which has been operated, pulling the slide assembly rearwardly to effect rocking of the paddle and positioning thereof by the cam 64 of the slide assembly. Thus tuning is efi'ected in the same fashion as would result from manual movement of the push-button. j

After the slide assembly reaches its rearmost position, effecting the tuning operation, the slide assembly is arrested and with it the slide 82. The piston 104, however, continues its travel, compressing spring 102 and carry: ing the arm 142 rearwardly to cause the end 144 of this arm to engage the disc 138 and thereby free the pin 136 from the end 134 of lever 122. As a result, the spring 120 moves the valve to the left, cutting off co'mmunication between opening and port 108 and opening port 108 to the atmosphere through slot 121. The piston is thus released, and with it the slide 82 which is pulled forwardly to its initial position by the spring 93. This occurs even if the push button has not been releasedflhe edge 83 withdrawing from the hook 80. Upon release of the push button, the lever 78 moves forwardly with it and, by the action of cam 84, is again raised out ofthe path of slide edge 83 so that the parts are restored to their normal positions. Spring 126 restores lever 122 as slide 30. moves to its right-hand position and the pin 136 is cleared by the lever end 134 and moves forwardly to the right thereof into position for reengagement in a subsequent the slide member 50 were of an overrunning type which would permit the slide member 50 to pull inwardly away from or relatively to the push button. However, the most desirable operation is that in which the vacuum action merely assists the manual pushing of the button '48. This result may be secured by providing a piston of such cross-sectional area that it alone would not suffice for effecting movement of the slide assembly. Desirably, the piston merely assumes some part of the force required. In other words, an assisting action rather than a completely efiiective power action in tuning is desirable. By reason of the pneumatic operation, the movements are of cushioned nature and there is absent the violence of movement which is characteristic of an electromagnetic assisting arrangement. g

It will be evident from what has been described that even when the pneumatic assist is inoperative, as when the engine is stationary, tuning'may be eifected,'taking place manually and with the same effort as is required in connection with present manual push button tuners. Difierences in the degree of power assistance afforded aseacoo may also occur, as when the degree of vacuum available is reduced by a wide open throttle during hill climbing. Desirably the piston area is so chosen as to require a minimum of finger pressure on a push button under ordinary normal speed driving conditions.

It will be evident that various changes in details of operation and construction may be made without departing from the invention as defined in the following claims.

What is claimed is:

1. Push button tuning means comprising a member settable to adjustable positions to efiect tuning, a plurality of push button devices each of which is efiective under manual manipulation to set said member to a corresponding position, pneumatic means set into operation by manipulation of each of said push button devices to assist the setting of said member by such device, and means operated by said pneumatic means for terminating the operation of said pneumatic means after such assisted setting of said member.

2. Push button tuning means comprising a member settable to adjustable positions to effect tuning, a plurality of push button devices including slides, each slide being efiective to set said member to a corresponding position, pneumatically operated means, a valve controlling the operation of said pneumatically operated means, and means efiective upon initial manual movement of each of said slides to couple the manipulated slide to said pneumatically operated means and to actuate said valve to effect movement of said pneumatically operated means to assist movement of the manipulated slide.

3. Push button tuning means comprising a member settable to adjustable positions to efiect tuning, a plurality of push button devices including slides, each slide being effective when moved to set said member to a corresponding position, pneumatically operated means, a valve controlling the operation of said pneumatically operated means, means effective upon initial manual movement of each of said slides to couple the manipulated slide to said pneumatically operated means and to actuate said valve to effect movement of said pneumatically operated means to assist movement of the manipulated slide, and means actuating said valve at the end of said assisting action to terminate the operation of said pneumatically operated means.

4. Push button tuning means comprising a member settable to adjustable positions to efiect tuning, a plurality of push button devices including slides, each slide being elfective when moved manually to set said member to a corresponding position, pneumatically operated means, a valve controlling the operation of said pneumatically operated means, and means efiective upon initial manual movement of each of said slides to couple the manipulated slide to said pneumatically operated means and to actuate said valve to eifect movement of said pneumatically operated means to assist movement of the manipulated slide.

5. Push button tuning means comprising a member settable to adjustable positions to effect tuning, a plurality of push button devices including slides, each slide being effective when moved manually to set said member to a corresponding position, pneumatically operated means, a valve controlling the operation of said pneumatically operated means, means effective upon initial manual movement of each of said slides to couple the manipulated slide to said pneumatically operated means and to actuate said valve to effect movement of said pneumatically operated means to assist movement of the manipulated slide, and means actuating said valve at the end of said assisting action to terminate the operation of said pneumatically operated means.

6. Push button tuning means comprising a member settable to adjustable positions to effect tuning, a plurality of push button devices each of which is effective under manual manipulation to set said member to a corresponding position, vacuum operated means set into operation by manipulation of each of said push button devices to assist the setting of said member by such device, and means operated by said vacuum operated means for terminating the operation of said vacuum operated means after such assisted setting of said member.

7. Push button tuning means comprising a member settable to adjustable positions to efiect tuning, a plurality of push button devices each of which is effective under manual manipulation to set said member to a corresponding position, power means energized and set into operation by manipulation of each of said push button devices to assist the setting of said member by such device, and means operated by said power means for deenergizing said power means after such assisted setting of said member.

8. Push button tuning means comprising a member settable to adjustable positions to eflect tuning, a plurality of push button devices each of which is efiective under manual manipulation to set said member to a corresponding position, pneumatically operated means to assist the setting of said member by each such device, and a valve controlled by manipulation of each of said push button devices and operable to control said pneumatically operated means.

9. Push button tuning means comprising a member settable to adjustable positions to effect tuning, a plurality of push button devices each of which is effective under manual manipulation to set said member to 2. corresponding position, vacuum operated means to assist the setting of said member by each such device, and a valve controlled by manipulation of each of said push button devices and operable to control said vacuum operated means.

References Cited in the file of this patent UNITED STATES PATENTS 1,298,226 Landis Mar. 25, 1919 1,524,923 Forsythe Feb. 3, 1925 1,665,909 Craig Apr. 10, 1928 1,997,575 Cummins Apr. 16, 1935 2,177,011 Whitehead Oct. 24, 1939 2,244,092 Wheeler June 3, 1941 2,367,860 Gersch Jan. 23, 1945 2,659,236 Allen Nov. 17, 1953 

